Yuki Mystery
by SilverDawn15
Summary: Kaoru and Mika Yuki live a normal life until a threat from the government caused them to become orphans. They lived for two years on the streets until Callaghan's daughter decides to adopt them. Now with the twins work along their new grandfather at his university, but what happens when Mika creates an invention that's soon stolen? Will she get it back or will it be too late?
1. Prologue

Yuki Mystery

Summary: Kaoru and Mika Yuki live a normal life until a threat from the government caused them to become orphans. They lived for two years on the streets until Callaghan's daughter decides to adopt them. Now with the twins work along their new grandfather at his university, but what happens when Mika meets the Big Hero 6 and creates a new invention that will soon be stolen? Will she get her invention back or will it be gone forever?

Prologue

"When are Mom and Dad getting home?" A thirteen year old girl with waist-length dark brown hair and gray eyes wearing a fuchsia jacket over a purple-and-orange striped shirt with a knee-length jean skirt and almond color boots asked as she looked out the window curiously. "It's been five hours and I don't think we can call the police yet."

The person she was talking to was a boy, the same age as her, with shoulder-length light brown hair and dark gray eyes wearing a dark red jacket over a gray t-shirt, dull blue jeans that were not washed for a year, and black running shoes. "Something doesn't add up," He said as he looked at his laptop again. "They went to a conference in the middle of the town and should've been back by now. So that means something happened to them on their way to or from the conference-"

"Kaoru, let it go," His sister said as she stared boredly at him. "If anything did happen, it would be that one of them just probably lost a bet and went to the bank to get more money."

"Oh yeah?" He asked as she replied with a "Yeah". "Then why did I find this letter from the government addressed to us and not Mom and Dad?" She swiped it out of his hand and opened it to see what the letter said. "Kao, I think you better read this." She said as she handed the letter to him with a shocked face.

He made a face at her before grabbing it out of her hand and reading it himself.

'To the kids of Miyako and Takeshi Yuki, consider this your first and last warning. We will deport you two from the country if you don't do as we say. Or else you'll never see your parents or anyone else again.' "They're threatening us!" He said as he looked at his sister's still shocked face. "What should we do?" She asked as he reread the letter.

"We run."

"WHAT?!" She shouted as she looked at him like he was crazy. "The government is threatening us, not Mom and Dad so we run and they can't catch us." He said like it was a brilliant plan. "Or we could get caught and be deported out of the country." She replied as she thought the plan wasn't brilliant at all. Which it wasn't.

"We'll just lie low for a few days until they forget about us and, BOOM! We're in the clear!" He explained as he grabbed a backpack and put a few perishable, but treasured, things in it. "It's foolproof, and even I might agree that it's a great plan!" His sister just looked at him like he was crazy, which he was. "Just trust me." He said as he packed another backpack with the remaining treasured perishables and gave it to her. She thought of the situation, if they run then the government won't find them and deport them from the country but if they stay or get caught while they run then they'll be deported.

Of course there was only one answer, and her brother had thought it through.

* * *

Part 2

"How long have we been running?" Mika asked as her brother looked through the _fourth _trashcan to find something at least edible for him or for his sister. It's been two years since the threat from the government, and Mika is starting to doubt that it was from them. After Kaoru couldn't find anything in the trashcan they walked to the next town to try to find something as a small dinner.

Bright lights, cars honking, and people either talking on their phones or with each other. "We're in San Fransokyo," Mika said as they walked towards a park. "Where a third of the population is the police!" They sat on the bench and put their stuff underneath so it wouldn't get stolen from them. "I don't wanna try to get dinner here." Kaoru said as he smiled at her sheepishly. She just groaned in return.

At the other side of the park was a woman in her early twenties with brown hair that reaches mid-back in a ponytail and blue eyes that were watching as the twins sat on the bench and one of them punched the other in the arm. _Where are their parents? _She thought as she walked towards them and immediately saw their bags underneath the bench.

"I'm telling you," The one on the left that sounded like a girl. "I don't think that threat was from them. If it was Mom and Dad would be home and we wouldn't have been running for two years." _WHAT?! _She thought as she kept listening. "Mi, I know that it came from them," The one on the right that sounded like a boy answered. "That's why my idea is working perfectly. We're not caught so they can't deport us from the country."

_Those poor kids... _"You really need to brush your teeth." 'Mi' said in a monotone voice. "You need to brush too! But you don't hear me complaining!" The boy retorted. "Excuse me." The woman said, making the two turn around to face her. They were thinner than what they should be, there was a patch of dirt on the girl's right cheek, their clothes were disheveled and faded, their hair were like huge nests, but their eyes looked like they never gave up hope.

"I'm Abigail Callaghan," She introduced herself to them. "Can you tell me who you two are?" They looked at each other before looking back at her. "I'm Mika Yuki," The girl answered before the boy could. "And this is my idiotic twin brother Kaoru, who had the 'smartest' idea to run away." As she said that last part, she glared at her brother.

"Why don't you two come with me and I'll figure out what happened to your parents." Abigail offered and they shrugged as they nodded. They grabbed their stuff from under the bench and followed her to a house across the street. It was a medium sized two-story house with silver-like tan walls, a dark blue shingled roof that looked like the last light of the sky before the night comes, a beautiful birch door, two modern-sized windows in the front, and an ivory colored fence at the sides of the house.

"Wow..." They said before she opened the door to let them in, and boy were they now shocked! The inside was a bit bigger with a half-kitchen and half-living room as one room. There was a plasma screen TV, one couch, and one loveseat in the living room part of the room. There was also a countertop island, a stove with a microwave above it, a fridge, a sink built into a counter, and lots of cabinets around and built into the island. The walls were a soft peach color and the floor was half russet-colored carpet and half tiled flooring. There was an oak spiral staircase in the corner of the room, probably leading to the bedrooms and bathrooms.

"Now lets see where they are." She said as she pressed a button on the wall and a part of the floor in front of the couch and loveseat separated itself so that another piece of the floor, holding lots of tracking equipment, came up in its place. The twins were stunned as they watched her turn on a laptop and pulled up a map of the country on a screen above the laptop.

"Last name: Yuki. First name- what's your parents names?" She asked as she filled in the search engine. "Takeshi and Nomikomu, for Mom: Nomi for short." Kaoru answered as he and Mika sat on the couch, careful to not get it dirty. She typed the information in and two dots appeared on the screen as a video of the security camera there showed what happened.

The results weren't promising.

"T-They're dead..." Mika whispered as she and Kaoru processed what happened. Their parents were beaten and struck by clubs before they died by being hanged from a railing. Abigail looked at the two before turning off the laptop and walking over to them before embracing them as they let their tears out. "I'll take care of you two," She said after they stopped crying and made them look at her. "I'll adopt you two."


	2. Chapter 1

Chapter One: Dino-bot and Hover Skates

Two Years Later...

"Just a little more...!" A sixteen year old boy with spiky black hair and brown eyes wearing a gray shirt underneath a dark purple hoodie with tan-colored pants that were rolled up at the end and silver-black shoes mumbled before ducking as a piece of his experiment broke from the experiment itself and flew in his direction. "Damn! If only I could figure out why my Motorized Bobyguard isn't working!" He shouted as he looked over the robot again.

"Maybe you forgot to add a Sharp GP2Y0A21YK0F Range Sensor for the eyes." A male voice said, making Hiro look at the door to see a fifteen year old boy with shoulder-length light brown hair and dark gray eyes wearing a darkish green jacket over a white dress shirt, camouflage-colored leggings that were too long to be shorts and too short to be pants, and gray-brown boots. "Who are you?" Hiro asked as he quickly looked over the stranger. "I'm Kaoru Yuki," The other boy answered. "Me and my twin sister Mika started here a month ago, and we've got some ideas that would be perfect!"

BOOM! "KAORU!"

"And that would be Mika." Kaoru said before running as the sound of pounding feet came closer. "COME HERE YOU LITTLE BAKA!" A female voice shouted as a multicolored blur ran past his office. "Mika, I know you're angry but - OW!" "That was for leaving _me _to work with _your _project!" Hiro poked his head into the hallway to see a fifteen year old girl with waist-length dark brown hair and furious gray eyes wearing a pale gray shirt with a dark stain at the bottom, black fingerless gloves which was grasping Kaoru's collar towards her, dark blue sweatpants, and very dark purple shoes.

"Just let me go please.." Kaoru pleaded but it looked like it wasn't going to happen. "Not until _you _go finish _your _project and let _me_ finish _mine_!" The girl shouted before turning around and intending to drag Kaoru back to their lab until she noticed Hiro watching them. "What are you staring at weirdo?!" She shouted at him before dragging her brother down the corridor and into a room two doors away from his workroom.

"That was weird.." He said as he went back into his workroom and then decided to try what Kaoru had said about the range sensor.

* * *

"Hey! Look at me!" Kaoru shouted excitedly as he put on yellow boots and pressed a gray button on the side which then the boots made a slight hum and he levitated a few feet off of the ground. "Be careful not to-" "OW!" "-hit your head on any of the shelves." Mika finished as she sighed and turned around to see him rubbing his head as he stared at the shelf he flew into.

"Idiot..." She mumbled before turning back to the dinosaur robot she was making adjustments on as she continued ignoring her brother who was floating around the room. "Do you think Mom will be there? Or Grandfather?" He asked as he watched his sister finish her project, which converted itself into a suitcase. "I think so since Grandfather is a _professor _here." She said as she watched her brother float to the ground and turn off the shoes.

"Okay, let's go!" He said as he dragged her to the showcase, luckily she was holding onto her project so she wouldn't lose it.

As they got to the showcase, they saw a lot of people there and found the group they were looking for. "Mom! Grandfather!" They shouted as they ran towards two people of the group while the rest looked with content... well all except one. Hiro stared at the twins in shock as he watched them talk to Professor Callaghan and Abigail about how well their projects will turn out.

**Up next: Mika Yuki**

"That's me," The brunette with waist-length hair and dark gray eyes replied as she picked up a suitcase. "Wish me luck!" As she went towards the stage, more and more people gathered around as she set her project up. "Okay, here I go." She said to herself before taking a deep breath. "Ladies and gentlemen, what I have here might look like an ordinary suitcase, but if you press one of the latches... and turn the frequency... you get this!"

A mash-up of 'The Park is Closed' and 'Nine to Survival Job' from the Jurassic World soundtrack was heard and people slowly lost interest until they saw that the suitcase was enlarging and shifting. That kept the people's attention. "I've seen this before," Abigail said to the Big Hero 6 group she was with as she watched her adopted daughter's project. "There is a _huge _twist at the end."

"Hurry up already!" Fred shouted, and instantly earned a glare from Mika. He smiled sheepishly and hung his head a bit which made her calm down and closed her eyes before she looked at her project. "This is Project Blue." She said as she gestured to it, and the audience saw a robotic Velociraptor right in front of them as music continued coming out of its' partly opened mouth before the music stopped.

"That's it?" Hiro asked before seeing the dino-bot open its' eyes and gave out a Tyrannosaur's roar. Everyone stared at the dino-bot before clapping and cheering in excitement as the robot stared and analyzed everyone. "That was just the beginning," Mika said as the robot turned to analyze her. "Project Blue is a combination of an MP3 player and a bodyguard. It will analyze the people around it and decide who its' master is, considering I designed her to be a Beta so her 'master' will be her 'Alpha'."

Everyone clapped in excitement as Mika bowed and pushed a button on the raptor's nose to shift it back into a suitcase before she picked it up and walked off stage. "That was awesome Mika!" Kaoru shouted as he slapped her on the back, which made her fall to the ground. "Oops."

**Up next: Kaoru Yuki**

"I'm up!" He said as he ran onto the stage, which he then tripped over a loose cord from an earlier project and caused his boots to hum. "Uh oh." He said as he slowly stood up before floating a few feet above the ground. "I'm gonna kill him." Mika said as she watched her brother try to turn off the shoes, but the button was stuck and if he took a closer look: there were very small sparks coming out. Then smoke suddenly covered the room and that was the last straw for his sister.

"KAORU!"


End file.
